Method and apparatus for treating material with a charged beam



un-nnvnl uuul 1957 KAZUMITSU TANAKA METHOD AND APPARATUS FOR TREATINGMATER 3,351,731 IAL WITH A CHARGED BEAM 2 Sheets-Sheet 1 Filed Oct. 5.1963 J II INVENTOR. K 7622" a.

1967 KAZUMITSU TANAKA 3,35

METHOD AND APP ARATUS FOR TREATING MATERIAL WITH A CHARGED BEAM FiledOct. 5, 1963 2 Sheets-Sheet 2 I I I I l I n i 8 INVENTOR.

BYKEMQJ Fig. I0 v4 401- United States Patent 3,351,731 WTHOD ANDAPPARATUS FOR TREATING MATERIAL WITH A CHARGED BEAM Kazumitsu Tanaira,Tokyo, Japan, assignor to Nihon Denshi Kabushiki Kaisha, Tokyo, Japan, acorporation of .lapan Filed Oct. 3, 1963, Ser. No. 313,665 Claimspriority, application Japan, Oct. 23, 1962, 37/ 47,304 9 Claims. (Cl.219-69) ABSTRACT OF THE DISCLOSURE An apparatus and method forcurvilinearly treating materials with a charged beam by applying amagnetic or electrostatic field to the material to be treated so as todeflect the charged beam within the material to be treated.

This application relates to method and apparatus for treating materialwith a charged beam and more particularly to method and apparatuswhereby curved cuts, grooves and bores can be made by treating materialwith a charged beam. In prior methods and apparatus for treatingmaterial with charged beams, it has been possible to make only straightcuts or grooves. This is due to the fact that in the use of priorapparaus for treating materials with charged beams, the beams passedthrough the material in straight lines only. I overcome this limitationby producing a field capable of deflecting charged particles in thematerial being treated while it is subjected to the charged beam. Thedeflecting field deflects the particles in the charged beam and causesthem to follow a curved path within the material being treated.

I also provide proper operating conditions within the material treatingzone by subjecting the material being treated to intermittent pulses ofthe charged beam.

The charged beam consists of charged particles, for example, an electronbeam or an ion beam. The charged particle deflecting field may be amagnetic field, an electrostatic field, or a combination of both.

In the accompanying drawings, I have illustrated certain presentlypreferred embodiments of my invention in which:

FIGURE 1 is a diagram illustrating the principle of my invention;

FIGURE 2. is a schematic diagram of apparatus used for carrying out myinvention;

FIGURES 3-7 inclusive illustrate articles formed by treating materialsin accordance with my invention;

FIGURE 8 is a schematic diagram partially illustrating a modification ofapparatus for carrying out my invention;

FIGURE 9 is a section along the lines IX-IX in FIGURE 8; and

FIGURE 10 is a schematic diagram illustrating a portion of a secondmodification of apparatus used for carrying out my invention.

Referring to FIGURE 1 of the drawings, material 1 to be treated isplaced between poles 2 and 3 of an electromagnet, the polarity of thepoles being indicated by the letters N and S. An electron beam 4 isfocused on the material, and the beam is deflected within the materialin a direction at right angles to magnetic flux 5 developed by thepoles. The electron beam is thereby curved in its passage through thematerial and, by controlling the amount of deflection of the electronbeam, cuts and grooves having any desired curve can be made in thematerial by bombardment by the electron beam.

FIGURE 2 is a schematic diagram of apparatus for carrying out myinvention. The material 1 to be treated is placed between the polepieces 2 and 3 of an electro- 3,351,731 Patented Nov. 7, 1967 magnet ona movable support 11, and an electron beam 4 is focused so that thepoint of minimum cross section of the beam falls on the surface of thematerial 1. The electron beam is emitted from an electron gun 7 having acathode 8 and an anode 9 and is focused by a condenser lens 10.

The magnetic polepieces 2 and 3 are energized by coils 12 and 12' andthey are connected by a yoke 13 which provides a magnetic flux returnpath.

A tubular shield 14 of material having high magnetic permeabilitysurrounds the path of the electron beam 4 and protects the beam fromdisturbance by magnetic flux from the poles 2 and 3, yoke 13 and coils12 and 12' during its passage from the electron gun 7 to the material 1.

The interior of the entire apparatus is maintained under a high vacuum,an outlet 15 being provided for exhausting the electron emitting systemA and an outlet 16 for exhausting the treating chamber B.

When the electron gun 7 is energized to make cuts or grooves in thematerial 1 being treated by means of the electron beam 4, the magneticpoles 2 and 3 are also energized to create a magnetic field passingthrough the material 1 in a direction at right angles to the axis of theelectron beam 4. The effect of the magnetic field is to deflect theelectrons in the electron beam in a direction at right angles both tothe direction of the magnetic field and to the direction of the electronbeam. The electrons in the electron beam therefore follow a curved paththrough the material being treated. The amount of the curvature can becontrolled by regulating the speed of the electrons and by regulatingboth the strength and direction of the magnetic flux created in thematerial by the pole pieces 2 and 3.

FIGURES 3-7 inclusive illustrate different cuts or grooves which can beformed in the material by my method and apparatus. The article shown inFIGURE 3 was formed by irradiating the material 1 with an electron beam,creating a magnetic field flowing through the material and at the sametime moving the material on the support 11 in the direction of the arrow17. The material was cut into two pieces, 1 and 1', each having auniformly curved surface.

In the article shown in FIGURE 4, a groove 18 was formed in the samemanner as the cut was made in the article shown in FIGURE 3. The articleshown in FIG URE 5 was made by a cut similar to that made in thematerial shown in FIGURE 3, and a second out similar to the first cutbut curving in the opposite direction. The oppositely directed cut wasmade by reversing the direction of the magnetic field created by thepole pieces 2 and 3, the direction of the field being changed byreversing the direction of the current flowing through the coils 12 and12'.

FIGURE 6 shows a bore having a single entrance and two outlets 19 and19' branching from the bore which has been cut in the material 1. In thearticle shown in FIGURE 7, a groove 18 has been out having a straightentrance and a curved outlet, the curve in the outlet having been formedby varying the strength of the magnetic field, the polarity of the fieldremaining constant.

FIGURE 8 is a schematic diagram showing another form of my invention inwhich several magnetic fields are created in the material being treatedby using two or more pairs of magnetic pole pieces of the same oropposite polarity. In the apparatus illustrated in FIGURE 8, the polepieces 2-3 and 2"3 have the same polarity, and the pole pieces 2'3' areof opposite polarity so that a bore 19 cut in the piece by the electronbeam 4 will be curved as shown in FIGURE 9.

FIGURE 10 illustrates diagrammatically a further modification of myinvention in which the axis of the electron beam forms with thedirection of the magnetic flux 5 passing through the material an angleof less than 9t). Due to the interaction between the electrons in theelectron beam and the magnetic flux, a spiral bore is cut in thematerial.

When cuts or grooves are being formed in material as described above,molecules in the portions of the material being treated may vaporize, bebombarded by electron beams, and thereby become ionized. These ionizedmolecules will be in the path of the electron beam and may disturb thedirection of the beam so that the desired shape of a cut or groove isnot obtained. To avoid this difliculty, I operate the electron gunintermittently so that the material being treated receives intermittentpulses of the electron beam. During the times that the electron beam isnot treating the material, the system used to maintain a high vacuum inthe apparatus draws away from the material the ionized molecules so thatwhen the beam is energized, it has a clear path to the material beingtreated. Pulsing of the electron gun can be accomplished in a number ofways, for example, by providing periodically a negative voltage to agrid forming part of the electron gun.

FIGURES 3-7, 9 and 10 show only a few of the many shapes of cuts andgrooves which can be formed in material by bombardment by a charged beamwhen a magnetic or electrostatic field is maintained in the material inaccordance with my invention. Any desired shape or configuration ofcuts, grooves, or bores can be obtained by adjustment of the speed ofthe electrons in the electron beam, adjustment of the angle between theelectron beam and the magnetic or electrostatic field, and by adjustmentof the strength and polarity of the magnetic or electrostatic field. Myinvention is particularly useful in the manufacture of miniaturizedparts.

While I have described a presently preferred embodiment of my invention,it is to be understood that it may be otherwise variously embodiedwithin the scope of the appended claims.

I claim:

1. A method of curvilinearly treating material with a charged beam whichcomprises,

(A) focusing a charged beam onto the material, and

(B) applying to the material a field capable of deflecting chargedparticles within the material, the direction of the deflecting fieldbeing at an angle to the direction of the charged beam so as tocurvilinearly treat the material.

2. A method of treating material with a charged beam as described inclaim 1 and including the step of varying the strength of the chargedparticle deflecting field.

3. A method of treating material with a charged beam as described inclaim 1 and including the step of changing the polarity of the chargedparticle deflecting field.

4. A method of treating material wtih a charged beam as described inclaim 1 and including the step of impinging thec harged beam onto thematerial in intermittent pulses.

5. Apparatus for curvilinearly treating material wtih a charged beamwhich comprises,

(A) a source of charged beams,

(B) a condenser lens for focussing charged beams from said source ontomaterial to be treated, and

(C) means for applying to the material to be treated a field capable ofdeflecting particles within the material, the direction of thedeflecting field being at an angle to the direction of the charged beamswhereby the beam curvilinearly treats said material within the material.

6. Apparatus for treating material with a charged beam as described inclaim 5 and including means for changing the strength of the deflectingfield.

7. Apparatus for treating material with a charged beam as described inclaim 5 and including means for changing the polarity of the deflectingfield.

8. Apparatus for treating material wtih a charged beam as described inclaim 5 and including means for operating said charged beam source inintermittent pulses.

9. Apparatus for treating material with a charged beam as described inclaim 5 and having a magnet for creating the deflecting field.

References Cited UNITED STATES PATENTS 2,267,752 12/1941 Ruska et a121969 X 2,932,588 4/1960 Frank. 3,033,974 5/1962 Schleich et a1. 219-117 3,151,231 9/1964 Steigerwald 219-121 RICHARD M. WOOD, PrimaryExaminer.

R. F. STAUBLY, Assistant Examiner.

1. A METHOD OF CURVILINEARLY TREATING MATERIAL WITH A CHARGED BEAMCOMPRISED, (A) FOCUSING A CHARGED BEAM ONTO THE MATERIAL, AND (B)APPLYING TO THE MATERIAL A FIELD CAPABLE OF DEFLECTING CHARGED PARTICLESWITHIN THE MATERIAL, THE DIREC-